Manzolini Libellula
The Manzolini Libellula was a 1950s Italian co-axial twin-rotor helicopter designed by Ettore Manzolini. "Libellula" is the Italian word for "Dragonfly".
| Libellula | |
|---|---|
| Role | Light experimental helicopter | 
| Manufacturer | Manzolini | 
| Designer | Ettore Manzolini | 
| First flight | 7 January 1952 | 
| Number built | 3 | 
Design and development
    
Ettore Manzolini established a company in Rome, Italy to develop a helicopter he had designed. The design was the Manzolini Libellula an unusual co-axial helicopter. The co-axial arrangement eliminating the need for an anti-torque rotor allowed the helicopter to have a twin fin arrangement. The Libellula (Registered I-MANZ) first flew on 7 January 1952. An improved version was the single-seat Libellula II which went on to gain Italian certification on 15 October 1962. A three-seater version (the Libellula III) was built and a four-seat Libellula IV was planned but Manzolini stopped development in the late 1960s.
Variants
    
- Libellula
 - Prototype, one built.
 - Libellula II
 - Prototype single-seat version powered by a 75kW (101hp) Walter Minor 4-III engine, one built.
 - Libellula III
 - Prototype two-seat version powered by a 104kW (140hp) Walter M 332 engine, one built but not flown.
 - Libellula IV
 - Proposed four-seat version powered by a 236kW (317shp) Allison 250-CT18 turboshaft, not built.
 
Specifications (Libellula II)
    
Data from Jane's All The World's Aircraft 1965–66[1]
General characteristics
- Crew: 1
 - Length: 4.85 m (15 ft 11 in)
 - Height: 3.06 m (10 ft 0 in)
 - Empty weight: 498 kg (1,098 lb)
 - Max takeoff weight: 650 kg (1,433 lb)
 - Powerplant: 1 × Walter Minor 4-III air-cooled 4-cylinder inline engine, 75 kW (101 hp)
 - Main rotor diameter: 2 × 9.00 m (29 ft 6 in)
 - Main rotor area: 127.2 m2 (1,369 sq ft)
 
Performance
- Maximum speed: 110 km/h (68 mph, 59 kn)
 - Cruise speed: 90 km/h (56 mph, 49 kn) (econ cruise)
 - Range: 200 km (120 mi, 110 nmi) max fuel, 10 min reserve
 - Service ceiling: 2,900 m (9,500 ft)
 - Rate of climb: 4.0 m/s (780 ft/min)
 
References
    
- Taylor 1965, p. 95.
 
- Apostolo, Giorgio. The Illustrated Encyclopedia of Helicopters. New York: Bonanza Books, 1984. Pg.123 ISBN 0-517-439352.
 - Taylor, John W. R. (1965). Jane's All The World's Aircraft 1965–66. London: Sampson Low, Marston & Co., Ltd.
 - The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985). Orbis Publishing.